This disclosure relates to a high pressure turbine for a gas turbine engine with a variable vane configuration.
A typical jet engine has multiple shafts or spools that transmit torque between turbine and compressor sections of the engine. In one example, a low speed spool generally includes a low shaft that interconnects a fan, a low pressure compressor, and a low pressure turbine. A high speed spool generally includes a high shaft that interconnects a high pressure turbine and a high pressure compressor.
Certain physical limitations of the engine affect engine characteristics such as the ultimate fuel burn characteristics, maintenance cost, and thrust ratings (takeoff vs. climb lapse rates), for example. One example of such a physical limitation relates to temperatures before, during, and after takeoff. Various components of the engine, such as those in the compressor and turbine sections of the engine for example, can be adversely affected by high temperatures. Thus, the engine is configured to include various systems and mechanisms for cooling purposes. However, during hot days it becomes even more difficult to provide enough cooling flow to provide for adequate turbine life, especially during takeoff and early climb.